Lens and mirror mounting.



W. CHURCHILL.

LENS AND MIRROR MOUNTING.

APPLICATION FILED no.4. 1013.

Patented June 30, 1914.

WILLIAM CHURCHILL, or Gamma, NEW YORK.

. LE S AND minnoa MOUNTING.

Specification ofLetters Patent. Application filed Decemberl, 1913.Serial No. 804,687.

Patented June 30, 19'] L;

To all whom it may concern:

'Be it known that I, WILLIAM CHURCHILL, a citizen of the United States,residing at Corning, in the county of Steuben and State v of New York,have invented new and useful Improvements in Lens and Mirror Mountings,of which the following is a spec1fication.

. My invention relates to improvements in lens and mirror mountings foruse in the art of signaling, more especially as applied to railroadpractice.

In my application Serial No. 697 ,327, filed May 14, 1912, I show adeviceespecially adapted for use in connection with a rail way signalsemaphore or similar signaling apparatus having, as a part thereof, amovable blade or target. The invention therein shown involves thereflection of light and the production of the signaling eflect by theuse of a movable signaling part upon which are, supported a casing, acorrugated lens and a reflector, said parts so supported constituting aunitary signaling member adapt-' ed to be so arranged that beams ofsubstantiallyparallel rays-as from a locomotive headlightfin a directiontoward sald unitarysignaling member and impinging on the surface of thelens thereof, are brought to focus on or adjacent to the surface of thereflector thereof, and then by reflection are caused to travel backwardthrough said lens in the direction of the source of lllustration, thereto be seen by an observer located at or adjacent to such source. Myinvention now to be described is intended to improve and render moreefficient the unitary signaling member set forth in said application.

In the accompan 'ng drawing, Figure 1 is a side view part y in sectionof the said unitary signaling member. Fig. 2 1s a rear view thereof.

In order to getreflected beams of maximum intensity from the unitarysignaling member, one or a series of which may be inserted in asemaphore blade or similar movable blade or target, it is necessary toproduce an accurate adjustment between the lens and the mirror. If theadjustment is inaccurate, the reflected beams will be dif- I tion ofcurvature and consequently of focal length. Furthermore, I have found itimadjustment of g of an inch should be sufiicient in all cases, and withsuch variation it is possible and desirable to carefully test the lensand mirror combination before placing it in service, and to give thecombination the precise adjustment capable of producin the maximumresults.-

Wit this preliminary explanation of the invention, reference is now madeto the drawing, 1n which 1 1s a casing preferably of substantiallyfrusto-conical form and adapted to be fitted to a semaphore arm, orsimilar movable blade or target, or to any other support, whethermovable or stationary. Th1s casing is preferably made of .sheet metal,its smaller end being closed as shown at 1. \Vithin this end ofthecasing is appropriately secured, as by hooked bolts :2, a mirror 3. Thelarger end 1 of the easing whichis of cylindrical form receives aflanged sleeve 4 adapted to have rotative movement. The cylindrical part1 is provided with a series of angular slots 5, as here shown three innumber, and through these 'slots pass screw bolts 6 having nuts (5, by

means of which bolts the sleeve 4, when it 'has beengiven the necessaryadjustment with respect to the axis of the casing, may be permanentlsecured. Over the outer or flanged end 0 the sleeve 4 is slipped a-divided ring 7, within which the outer edge of the corrugated lens 8 isfitted. The split ring is adapted to telescope at its meeting ends, asat to each of which is attached a clip or In 9. Through these lugspasses a bolt 10 which may be threaded as shown in Fig. 2 in one of thelugs 9, or if preferred a nut may be used upon the said end of the bolt.By suchmcans'the lens after it has been inserted within the divided ring7 may be secured therein, and also readily released.

In operation, the casing 1 with its adjuncts when placed in the requiredposition, and it is desired to adjust the lens to the required distance,this may be done by the rotation of the sleeve 4, and when it is broughtin place it may be tightened by means of the bolts 6. The mounting ispractically dusttight if the lens is secured properly in position. Bythe means described it is possible to vary the distance between the lensand the reflector within the required limits while the axes of bothpreserve their proper relation to each other, that is to say, the axisof the mirror and the axis of the lens both fall on thethose previouslyused.

Asimple method of testing the optical combinations is to set them up ata distance of about fifty feet from a source of approx1,.

mately parallel rays, such as an ordinary corrugated lens, with a lampbehind it, and

to then fasten a small pieceof mirror to the front face of the lens atsuch an angle that the image of the lens-reflector combination projectedback and striking it is deflected to one side. An observer stationshimself so that he can observe the image of the combination deflectedfrom the mirror. The distance between the lens and the mirror in themounting is now varied until it is noted by the observer that the entirelens appears to be illuminated. When this efi'ect is noticed it isobvious that the adjustment is correct, as it; is made permanent in themanner hereinbefore described.- If for any reason it is desired toproduce a divergent -beam from the lens reflector combination, in-

stead of a narrow beam of approximately parallel rays, it is feasible toset the combination by trial, as described, at exactly the distanceneeded in order to produce any required amount of spread.

While I have described my improved lens and mirror mounting in the formand having the means of adjustment found to be practicable and preferredby me, it is obvious that my invention is capable of variation in formhaving structural and operative features which may suggest themselves tothe skilful mechanic, without departing from what is herein claimed. V I

Having thus described my invention, I claim 1. A unitary signalingmember for receiving light from a source exterior to said member andreflecting back the light toward such source, the same consisting in acasing having a cylindrical front portion, a mirror means associatedwith the cylindrical part of the casing and said sleeve whereby, on suchrotative movement of the latter, the

lens may be 'a'xially adjusted and-the distance between it and themirror varied, substantially as set forth.

2. A unitary signaling member for receiving light from a-source exteriorto said member and reflecting back the light toward such source, thesame consisting in a casing having a cylindrical front portion, thelatter being provided with angular slots, a mirror fixedly placed at therear of said casing and closing the same, a sleeve fitted to and adaptedto have rotative movement with respect to the cylindrical frontportion-of said casing, a lens carried by the sleeve, and screw boltspassing through said slots and the cylindrical front portion of saidcasing, the arrangement being such that on the loosening of said screwbolts rotative movement of'said sleeve with respect to said cylindricalpart of the casing is permitted, the lens axially adjusted, and thedistance between it and the mirror varied, substantially as set forth.

3. A unitary signaling member for receiving light from a source exteriorto said member and reflecting back the light toward such source, thesame consisting in a casing having a cylindrical front portion, a mirrorfixedly placed at the rear of said casing and closing the same, a sleevefitted to and adapted to have rotative movementwith respect to thecylindrical front portion of said casing, a divided ring carried by saldsleeve, a lens supported by said divided ring, means for clamping thelens within the divided ring, and means associated wlth the cyl1n dricalpart of the casing and said sleeve whereby, on such rotative movement ofthe I WILLIAM CHURCHILL.

Witnesses: I

EMILIO PAsoUooI, HENRY PHELPS GAGE.

